Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description should disclose behavioral traits. It only says 'get a list of agents' without mentioning pagination, sorting, limits beyond the schema, or any side effects. It doesn't state that it is read-only or describe how the limit parameter affects results. The description adds minimal value beyond the tool name and schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.